Liquid level detection circuit, device and liquid level detection method

Abstract

The application discloses a liquid level detection circuit, device and method, which increases a second detection impedance in parallel with an original first detection impedance, and configures the state of two detection impedance loops through a first control pin and a second control pin of the detection circuit respectively. When a detection voltage is applied, the voltage level on one side of the two detection impedances is first pulled low, the current of the detection circuit is increased in the form of reducing the impedance of the detection circuit, so that the liquid between the two detection electrodes is accelerated to ionize and reach a steady state as soon as possible. Meanwhile, in combination with the control of delay detection, after the set time of satisfying the ionization of the liquid to reach a steady state is reached, the second control pin is configured to be in a high resistance state, and the first control pin maintains an output low level, so that the normal detection circuit is restored. Then, the liquid level voltage is obtained through the voltage division of the first detection impedance, so that the technical effects of quickly and stably obtaining the liquid level voltage and realizing faster and more real detection of the liquid level are achieved.

Description

Technical Field

[0001] This invention belongs to the field of liquid level detection technology, specifically, it relates to a liquid level detection circuit, device and liquid level detection method. Background Technology

[0002] Washing machines with automatic detergent dispensing function have their automatic detergent dispensing device located inside the washing machine, so users cannot directly see the detergent level and therefore need to monitor the detergent level.

[0003] One existing method for detecting detergent level involves placing a probe or electrode inside the detergent dispenser and determining the detergent level based on the conductivity of the probe or electrode. Figure 1 In one detection example shown, the probe includes a first electrode Pin1 and a second electrode Pin2, which are positioned opposite each other at the liquid level to be detected. The detection power supply terminal Vout is connected to the first electrode Pin1, and the second electrode Pin2 is connected to a voltage divider resistor R2 and an RC filter circuit. The voltage divider resistor R2 is grounded, and the RC filter circuit includes a resistive element R1 and a capacitive element C1. The main control chip detects the liquid level voltage through the I / O pin Det. During detection, the detection power supply terminal Vout is controlled to output a detection voltage to the first electrode Pin1, and the voltage at Det is immediately detected. The position of the liquid level is determined based on the voltage value.

[0004] This detection method using built-in probes or electrodes has the following problem: when the resistive element R1 and / or the capacitive element C1 changes, the voltage detected by Det varies greatly. For example... Figure 2 and Figure 3 As shown, Figure 2 The figure shows that when C1 = 0.1uF, the peak voltage detected by Det is 1.91V. Figure 3 The figure shows that when C1 = 1uF, the peak voltage detected by Det is 1.62V. It can be seen that in this liquid level detection method, a slight change in the hardware filter capacitor will change the detected peak voltage, which will affect the accuracy of the liquid level detection and the true state. Summary of the Invention

[0005] The purpose of this invention is to propose a liquid level detection circuit, device, and method. A second detection impedance is added to the liquid level detection circuit in parallel with the original first detection impedance. The states of the two detection impedances are controlled by two control pins. When a detection voltage is applied to the detection power supply terminal, the level of one side of the two detection impedances is first pulled down. By reducing the impedance of the detection circuit, the current of the detection circuit is increased, thereby promoting accelerated ionization of the liquid between the two detection electrodes and reaching a steady state as quickly as possible. Combined with delayed detection control, after the detection circuit returns to normal, the liquid level voltage is obtained through the voltage division of the first detection impedance, thus achieving rapid and accurate acquisition of the liquid level voltage and realizing a faster and more accurate liquid level detection effect.

[0006] The present invention is implemented using the following technical solutions:

[0007] A liquid level detection circuit is proposed, comprising:

[0008] The detection electrode includes a first detection electrode and a second detection electrode, which are disposed at the liquid level to be detected at a distance from each other.

[0009] The detection power supply terminal is connected to the first detection electrode and is controlled to provide a detection voltage to the first detection electrode.

[0010] The filter circuit includes a first resistive element and a first capacitive element connected in series; wherein the first capacitive element is grounded and the first resistive element is connected to the second detection electrode;

[0011] The detection circuit, whose detection terminal is connected to the node between the first resistive element and the first capacitive element, is used to detect the liquid level voltage by detecting the energized state of the second detection electrode; it also includes:

[0012] The first detection impedance has one end connected to the second detection electrode and the other end connected to the first control pin of the detection circuit.

[0013] The second detection impedance has one end connected to the second detection electrode and the other end connected to the second control pin of the detection circuit.

[0014] The detection circuit configures the first control pin and the second control pin to output a low level when the detection voltage is applied to the first detection electrode; and configures the second control pin to a high impedance state after a set time, and detects the liquid level voltage of the second detection electrode via the detection terminal.

[0015] Furthermore, the detection circuit detects the liquid level voltage of the second detection electrode via the detection terminal, specifically as follows:

[0016] After a second set time following the second control pin being configured to a high-resistance state, the liquid level voltage of the second detection electrode is detected via the detection terminal.

[0017] Furthermore, the set time is 100ms, and the second set time is 200ms.

[0018] Furthermore, the set time is 50ms, and the second set time is 150ms.

[0019] A liquid level detection device is proposed, comprising a liquid level detection circuit, the liquid level detection circuit including:

[0020] The detection electrode includes a first detection electrode and a second detection electrode, which are disposed at the liquid level to be detected at a distance from each other.

[0021] The detection power supply terminal is connected to the first detection electrode and is controlled to provide a detection voltage to the first detection electrode.

[0022] The filter circuit includes a first resistive element and a first capacitive element connected in series; wherein the first capacitive element is grounded and the first resistive element is connected to the second detection electrode;

[0023] The detection circuit, whose detection terminal is connected to the node between the first resistive element and the first capacitive element, is used to detect the liquid level voltage by detecting the energized state of the second detection electrode; it also includes:

[0024] The first detection impedance has one end connected to the second detection electrode and the other end connected to the first control pin of the detection circuit.

[0025] The second detection impedance has one end connected to the second detection electrode and the other end connected to the second control pin of the detection circuit.

[0026] The detection circuit configures the first control pin and the second control pin to output a low level when the detection voltage is applied to the first detection electrode; and configures the second control pin to a high impedance state after a set time, and detects the liquid level voltage of the second detection electrode via the detection terminal.

[0027] A liquid level detection method is proposed and applied to a liquid level detection device, the liquid level detection device comprising:

[0028] The detection electrode includes a first detection electrode and a second detection electrode, which are disposed at the liquid level to be detected at a distance from each other.

[0029] The detection power supply terminal is connected to the first detection electrode and is controlled to provide a detection voltage to the first detection electrode.

[0030] The filter circuit includes a first resistive element and a first capacitive element connected in series; wherein the first capacitive element is grounded and the first resistive element is connected to the second detection electrode;

[0031] The detection circuit has its detection terminal connected to the node between the first resistive element and the first capacitive element, and is used to detect the liquid level voltage by detecting the energized state of the second detection electrode.

[0032] The first detection impedance has one end connected to the second detection electrode and the other end connected to the first control pin of the detection circuit.

[0033] The second detection impedance has one end connected to the second detection electrode and the other end connected to the second control pin of the detection circuit; the method includes:

[0034] When the detection voltage is applied to the first detection electrode in a controlled manner, the first control pin and the second control pin are configured to output a low level, so as to pull down one side of the first detection impedance and the second detection impedance via the first control pin and the second control pin;

[0035] After a set time, the second control pin is configured to be in a high-impedance state, so as to set the loop of the second detection impedance to a high-impedance state via the second control pin;

[0036] The detection terminal is controlled to detect the liquid level voltage of the second detection electrode.

[0037] Furthermore, controlling the detection terminal to detect the liquid level voltage of the second detection electrode specifically includes:

[0038] After a second set time following the second control pin being configured to a high-resistance state, the liquid level voltage of the second detection electrode is detected via the detection terminal.

[0039] Furthermore, the set time is 100ms, and the second set time is 200ms.

[0040] Furthermore, the set time is 50ms, and the second set time is 150ms.

[0041] Furthermore, the method also includes setting the normal state of the first control pin to a low level.

[0042] Compared with the prior art, the advantages and positive effects of the present invention are as follows: In the liquid level detection circuit, device, and method proposed in this invention, the liquid level detection circuit includes a detection electrode, a detection power supply terminal, a filter circuit, a detection circuit, and a first detection impedance and a second detection impedance. Compared with the existing liquid level detection circuit, the present invention adds a second detection impedance in parallel with the original first detection impedance, and controls the state of the two detection impedances respectively through the first control pin and the second control pin of the detection circuit. When the detection power supply terminal is applied with a detection voltage, the level of one side of the two detection impedances is first pulled low, and the state of the two detection impedances is reduced by lowering the voltage level. By using a low detection circuit impedance method to increase the current in the detection circuit, the liquid between the two detection electrodes is accelerated to ionize and reach a steady state as quickly as possible. At the same time, combined with the control of delayed detection, after the set time required for the liquid to reach a steady state through ionization is reached, the second control pin is configured to be in a high impedance state, thereby setting the loop of the second detection impedance to a high impedance state. The first control pin maintains a low output level, pulling down the level on one side of the first detection impedance, thereby restoring the normal detection circuit. Then, the liquid level voltage is obtained through the voltage division of the first detection impedance, thereby achieving the technical effect of quickly and stably obtaining the liquid level voltage and realizing faster and more accurate liquid level detection.

[0043] Furthermore, after configuring the second control pin to be in a high-impedance state, the liquid level voltage is detected after a second set time delay. By delaying for the second set time, the liquid level is detected when the liquid level voltage is in a more stable and accurate state, thus achieving the technical effect of quickly, stably and accurately obtaining the liquid level voltage and improving the accuracy of liquid level detection.

[0044] Furthermore, compared to existing methods for detecting peak liquid level voltage, the liquid level detection circuit and delay detection method based on this invention detect the liquid level voltage after promoting the liquid to reach a steady state as quickly as possible through high current. This avoids the influence of changes in resistive and / or capacitive components in the hardware circuit on the peak current, thereby improving the reliability of liquid level detection.

[0045] Other features and advantages of the present invention will become clearer after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of an existing liquid level detection circuit;

[0048] Figure 2 for Figure 1 One of the schematic diagrams of the voltage detected by the existing liquid level detection circuit is shown;

[0049] Figure 3 for Figure 1 The second schematic diagram of the voltage detected by the existing liquid level detection circuit is shown.

[0050] Figure 4 This is a schematic diagram of the liquid level detection circuit proposed in this invention;

[0051] Figure 5 This is a flowchart of the liquid level detection method in Embodiment 1 of the present invention;

[0052] Figure 6 This is a schematic diagram of liquid level voltage detection in Embodiment 1 of the present invention;

[0053] Figure 7 This is a schematic diagram of liquid level voltage detection in Embodiment 2 of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0057] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0058] The liquid level detection circuit proposed in this invention, such as Figure 4 As shown, it includes:

[0059] The detection electrode includes a first detection electrode 11 and a second detection electrode 12, which are spaced apart at the liquid level to be detected. Taking the detergent dispenser of a washing machine as an example, the first detection electrode 11 and the second detection electrode 12 are spaced apart at the height of the liquid level to be detected inside the detergent dispenser.

[0060] A detection electrical module, installed on the exterior of a device containing the liquid to be tested, such as the outer wall of a detergent dispenser, includes:

[0061] The power supply terminal V is connected to the first detection electrode 11, which can be controlled to output or not output. When the output detection voltage is applied to the first detection electrode 11, if the liquid level reaches the level to be detected, the first detection electrode 11 and the second detection electrode 12 are simultaneously submerged in the liquid. Based on the current released by the first detection electrode 11, the liquid particles are ionized. After reaching a steady state, based on the conductivity of the liquid, the second detection electrode 12 is connected to the first detection electrode 11, so that the liquid level voltage can be obtained on the second detection electrode 12.

[0062] The filter circuit includes a first resistive element R1 and a first capacitive element C1 connected in series, wherein the first capacitive element C1 is grounded and the first resistive element R1 is connected to the second detection electrode 12.

[0063] The detection circuit U has its detection terminal DET connected to the node between the first resistive element R1 and the first capacitive element C1, and is used to detect the liquid level voltage by detecting the energization state of the second detection electrode 12.

[0064] The detection circuit U here can be the main control chip of the host, such as the main control chip of a washing machine or a dishwasher, or it can be a circuit that acquires voltage signals and converts them into recognizable levels. This invention does not impose any specific limitations.

[0065] The first detection impedance R2 is connected at one end to the second detection electrode 12 and at the other end to the first control pin P1 of the detection circuit U. Normally, the detection circuit U detects the liquid level voltage based on the voltage division of the first detection impedance R2.

[0066] The second detection impedance R3 is connected at one end to the second detection electrode 12 and at the other end to the second control pin P2 of the detection circuit U.

[0067] Based on the above liquid level detection circuit architecture, the liquid level detection method proposed in this invention is as follows: when the detection circuit U outputs a detection voltage at the detection power supply terminal V and applies it to the first detection electrode 11, the first control pin P1 and the second control pin P2 are configured to output a low level, pulling down the level of one side of the first detection impedance R2 and the second detection impedance R3. After a set time T, the second control pin P2 is configured to be in a high impedance state, thereby setting the loop of the second detection impedance R3 to a high impedance state, and the liquid level voltage of the second detection electrode 12 is detected via the detection terminal DET.

[0068] Based on the above, compared with the existing liquid level detection circuit, the present invention adds a second detection impedance R3 to the liquid level detection circuit, which is connected in parallel with the original first detection impedance R2. The states of the two detection impedances are configured through the first control pin P1 and the second control pin P2 of the detection circuit U, respectively. When the detection power supply terminal V applies a detection voltage, the detection circuit first pulls down the level of one side of the two detection impedances by configuring the two control pins. By connecting the two detection impedances in parallel, the impedance of the detection circuit is reduced, thereby increasing the current of the detection circuit and promoting the accelerated ionization of the liquid between the two detection electrodes to reach a steady state as soon as possible. At the same time, combined with the control of delayed detection, after the set time T for liquid ionization to reach a steady state is reached, the second control pin P2 is configured to be in a high impedance state, and then the second detection impedance R3 is set to a high impedance state. The first control pin P1 is configured to maintain a low output level, pulling down the level of one side of the first detection impedance R2, thereby restoring the normal detection circuit. Then, the liquid level voltage is obtained by the voltage division of the first detection impedance R2, thereby achieving the technical effect of quickly and stably obtaining the liquid level voltage and realizing faster and more accurate liquid level detection.

[0069] The set time T here is related to the impedance values ​​of the first detection impedance R2 and the second detection impedance R3. The smaller the equivalent impedance after the two are connected in parallel, the larger the current of the detection circuit, and the smaller the set time T is. It can be set according to the actual situation.

[0070] In some embodiments of the present invention, when the detection circuit U detects the liquid level voltage of the second detection electrode 12 via the detection terminal DET, in order to improve the detection stability and accuracy, the following control method can be used: after configuring the second control pin P2 to be in a high-impedance state, a second set time T2 is delayed, and the detection circuit U then detects the liquid level voltage of the second detection electrode 12 via its detection terminal DET; by delaying the second set time T2, the liquid level is detected again in a more stable and accurate state, thereby achieving the technical effect of quickly, stably and accurately obtaining the liquid level voltage and improving the liquid level detection accuracy.

[0071] Furthermore, compared to existing methods for detecting peak liquid level voltage, the liquid level detection circuit and delay detection method based on this invention detect the liquid level voltage after promoting the liquid to reach a steady state as quickly as possible through high current. This avoids the influence of changes in resistive and / or capacitive components in the hardware circuit on the peak current, thereby improving the reliability of liquid level detection.

[0072] The following two specific embodiments illustrate in detail the liquid level detection method when the liquid level detection circuit proposed in this invention is applied in a liquid level detection device.

[0073] Example 1

[0074] This embodiment takes the liquid level detection circuit proposed above as an example of detergent liquid level detection in a washing machine. It is applied to the detection of detergent liquid level in the detergent box. The liquid level detection circuit is integrated into a liquid level detection device and installed as a whole module on the outer wall of the detergent box.

[0075] The first detection electrode 11 and the second detection electrode 12 extend into the detergent box and are spaced apart at the height of the liquid level to be detected inside the detergent box; if the liquid level is to be measured at multiple points, a set of detection electrodes is set at each corresponding position.

[0076] The liquid level detection device, which includes a liquid level detection circuit, is connected to the main control chip of the washing machine via a connecting wire, so that the main control chip of the washing machine can act as a detection circuit or receive the liquid level voltage detected by the detection circuit.

[0077] like Figure 5 As shown, the liquid level detection method based on this liquid level detection circuit includes the following steps:

[0078] Step S51: After receiving the liquid level detection command, configure the first control pin and the second control pin to output a low level, and pull down the level of one side of the first detection impedance and the second detection impedance.

[0079] The states of the two detection impedances are set by the outputs of the first control pin P1 and the second control pin P2 of the detection circuit U. Before or simultaneously with the application of the detection voltage to the detection power supply terminal V, the outputs of the first control pin and the second control pin are configured to be low, thereby pulling down the level of one side of the two detection impedances. The impedance of the detection circuit is reduced by connecting the two detection impedances in parallel, thereby increasing the current of the detection circuit and promoting the accelerated ionization of the liquid between the two detection electrodes to reach a steady state as soon as possible.

[0080] Step S52: Control the output detection voltage from the detection power supply terminal to the first detection electrode.

[0081] The detection voltage is applied to the first detection electrode 11 by controlling the power supply terminal V to output the detection voltage.

[0082] Step S53: Configure the second control pin to be in a high-impedance state after a set time.

[0083] After the set time T required for the liquid to reach a steady state through ionization is reached, the detection circuit U configures the second control pin P2 to be in a high-impedance state, thereby setting the loop of the second detection impedance R3 to a high-impedance state. The first control pin P1 is configured to maintain a low output level, thereby pulling down the level on one side of the first detection impedance R2, thus restoring the normal detection circuit.

[0084] Step S54: After the second set time, the liquid level voltage is detected via the detection terminal.

[0085] After the second detection impedance R3 loop is configured in a high-resistance state, the liquid ionization reaches a stable state, and the detection circuit U detects the liquid level voltage of the second detection electrode 12 via the detection terminal DET as the stable voltage after the peak value. To improve detection stability and accuracy, in this embodiment, after configuring the second control pin P2 in a high-resistance state, a second set time T2 is delayed, and the detection circuit U then detects the liquid level voltage of the second detection electrode 12 via its detection terminal DET. By delaying for the second set time T2, the liquid level is detected again in a more stable and accurate state, achieving the technical effect of quickly, stably, and accurately acquiring the liquid level voltage, thereby improving the accuracy of liquid level detection.

[0086] In embodiments of the present invention, such as Figure 6 As shown, taking a set time of 100ms as an example, the liquid level voltage basically reaches a stable state after 100ms. After a second set time of 200ms, the liquid level voltage reaches a completely stable state. That is, a stable and accurate liquid level voltage can be obtained after 300ms. Compared with the existing method of detecting peak voltage, the stable voltage is not affected by the changes of resistive and / or capacitive components in the hardware circuit, thus improving the reliability of liquid level detection.

[0087] Example 2

[0088] This embodiment takes the liquid level detection circuit proposed above as an example of applying it to the liquid level detection of the outer drum of a washing machine. It is used to detect the washing liquid level in the washing machine. The liquid level detection circuit is integrated into a liquid level detection device and installed as a whole module inside the washing machine shell.

[0089] The first detection electrode 11 and the second detection electrode 12 extend into the outer cylinder and are spaced apart at the height of the liquid level to be detected inside the outer cylinder; if the liquid level is measured at multiple points, a set of detection electrodes is set at each corresponding position.

[0090] The liquid level detection device, which includes a liquid level detection circuit, is connected to the main control chip of the washing machine via a connecting wire, so that the main control chip of the washing machine can act as a detection circuit or receive the liquid level voltage detected by the detection circuit, thereby implementing the washing program based on the liquid level detection.

[0091] The liquid level detection method based on this liquid level detection circuit includes the following steps:

[0092] 1. Upon receiving the liquid level detection command, configure the first control pin and the second control pin to output a low level, thereby pulling down the level of one side of the first detection impedance and the second detection impedance.

[0093] The outputs of the first control pin P1 and the second control pin P2 of the detection circuit U respectively set the state of the two detection impedances. Before or at the same time as the detection power supply terminal V applies the detection voltage, the output of the first control pin and the second control pin is configured to be low, which pulls the level of one side of the two detection impedances low. The impedance of the detection circuit is reduced by connecting the two detection impedances in parallel, thereby increasing the current of the detection circuit and promoting the accelerated ionization of the liquid between the two detection electrodes to reach a steady state as soon as possible.

[0094] 2. Control the output detection voltage from the power supply terminal to the first detection electrode.

[0095] The detection voltage is applied to the first detection electrode 11 by controlling the power supply terminal V to output the detection voltage.

[0096] 3. Configure the second control pin to be in a high-impedance state after a set time.

[0097] After the set time T required for the liquid to reach a steady state through ionization is reached, the detection circuit U configures the second control pin P2 to be in a high-impedance state, thereby setting the loop of the second detection impedance R3 to a high-impedance state. The first control pin P1 is configured to maintain a low output level, thereby pulling down the level on one side of the first detection impedance R2, thus restoring the normal detection circuit.

[0098] 4. After the second set time, the liquid level voltage is detected via the detection terminal.

[0099] After the second detection impedance R3 loop is configured in a high-resistance state, the liquid ionization reaches a stable state, and the detection circuit U detects the liquid level voltage of the second detection electrode 12 via the detection terminal DET as the stable voltage after the peak value.

[0100] To improve detection stability and accuracy, this embodiment configures the second control pin P2 to be in a high-impedance state, and then delays for a second set time T2. The detection circuit U then detects the liquid level voltage of the second detection electrode 12 via its detection terminal DET. By delaying for the second set time T2, the liquid level is detected again when the liquid level voltage is more stable and accurate, achieving the technical effect of quickly, stably and accurately acquiring the liquid level voltage, thereby improving the accuracy of liquid level detection.

[0101] In embodiments of the present invention, such as Figure 7As shown, taking a set time of 50ms as an example, the liquid level voltage basically reaches a stable state after 50ms. After a second set time of 150ms, the liquid level voltage reaches a completely stable state. That is, a stable and accurate liquid level voltage can be obtained after 200ms. Compared with the existing method of detecting peak voltage, the stable voltage is not affected by the changes of resistive and / or capacitive components in the hardware circuit, thus improving the reliability of liquid level detection.

[0102] It should be noted that, in the specific implementation process, the control part mentioned above can be implemented by a hardware processor executing computer-executable instructions in software form stored in memory, which will not be elaborated here. The programs corresponding to the actions performed by the control can all be stored in the computer-readable storage medium of the system in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0103] The computer-readable storage media mentioned above may include volatile memory, such as random access memory; may also include non-volatile memory, such as read-only memory, flash memory, hard disk or solid-state drive; and may also include combinations of the above types of memory.

[0104] The term "processor" as mentioned above can also refer to a collective term for multiple processing elements. For example, a processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor, and it can also be a special-purpose processor.

[0105] It should be noted that the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. Liquid level detection circuit, including: The detection electrode includes a first detection electrode and a second detection electrode, which are disposed at the liquid level to be detected at a distance from each other. The detection power supply terminal is connected to the first detection electrode and is controlled to provide a detection voltage to the first detection electrode. The filter circuit includes a first resistive element and a first capacitive element connected in series; wherein the first capacitive element is grounded and the first resistive element is connected to the second detection electrode; The detection circuit has its detection terminal connected to the node between the first resistive element and the first capacitive element, and is used to detect the liquid level voltage by detecting the energized state of the second detection electrode. Its characteristic is that it further includes: The first detection impedance has one end connected to the second detection electrode and the other end connected to the first control pin of the detection circuit. The second detection impedance has one end connected to the second detection electrode and the other end connected to the second control pin of the detection circuit. The detection circuit configures the first control pin and the second control pin to output a low level when the detection voltage is applied to the first detection electrode; and configures the second control pin to a high impedance state after a set time, and detects the liquid level voltage of the second detection electrode via the detection terminal.

2. The liquid level detection circuit according to claim 1, characterized in that, The detection circuit detects the liquid level voltage of the second detection electrode via the detection terminal, specifically as follows: After a second set time following the second control pin being configured to a high-resistance state, the liquid level voltage of the second detection electrode is detected via the detection terminal.

3. The liquid level detection circuit according to claim 2, characterized in that, The first set time is 100ms, and the second set time is 200ms.

4. The liquid level detection circuit according to claim 2, characterized in that, The first set time is 50ms, and the second set time is 150ms.

5. A liquid level detection device, characterized in that, Includes the liquid level detection circuit as described in any one of claims 1-4.

6. A liquid level detection method, applied in a liquid level detection device, the liquid level detection device comprising: The detection electrode includes a first detection electrode and a second detection electrode, which are disposed at the liquid level to be detected at a distance from each other. The detection power supply terminal is connected to the first detection electrode and is controlled to provide a detection voltage to the first detection electrode. The filter circuit includes a first resistive element and a first capacitive element connected in series; wherein the first capacitive element is grounded and the first resistive element is connected to the second detection electrode; The detection circuit has its detection terminal connected to the node between the first resistive element and the first capacitive element, and is used to detect the liquid level voltage by detecting the energized state of the second detection electrode. The first detection impedance has one end connected to the second detection electrode and the other end connected to the first control pin of the detection circuit. The second detection impedance has one end connected to the second detection electrode and the other end connected to the second control pin of the detection circuit. The method is characterized by comprising: When the detection voltage is applied to the first detection electrode in a controlled manner, the first control pin and the second control pin are configured to output a low level, so as to pull down one side of the first detection impedance and the second detection impedance via the first control pin and the second control pin; After a set time, the second control pin is configured to be in a high-impedance state, so as to set the loop of the second detection impedance to a high-impedance state via the second control pin; The detection terminal is controlled to detect the liquid level voltage of the second detection electrode.

7. The liquid level detection method according to claim 6, characterized in that, Controlling the detection terminal to detect the liquid level voltage of the second detection electrode specifically includes: After a second set time following the second control pin being configured to a high-resistance state, the liquid level voltage of the second detection electrode is detected via the detection terminal.

8. The liquid level detection method according to claim 7, characterized in that, The first set time is 100ms, and the second set time is 200ms.

9. The liquid level detection method according to claim 7, characterized in that, The first set time is 50ms, and the second set time is 150ms.

10. The liquid level detection method according to claim 6, characterized in that, The method further includes: The first control pin is set to a low level as its normal state.

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